str2str (version 1.0.0)

t_list: Transpose a List

Description

t_list transposes a list, similar to what t.default does for matrices. t_list assumes the structure of each x element is the same. Tests are done to ensure the lengths and names are the same for each x element. The returned list has list elements in the same order as in x[[1]].

Usage

t_list(x, rtn.atomic = FALSE)

Value

list where each element is from those in x[[1]] and each element of the returned object has a subelement for each element in x.

Arguments

x

list where each element has the same structure.

rtn.atomic

logical vector of length 1 specifying whether the returned list should be a list of atomic vectors (TRUE) rather than a list of lists (FALSE).

Details

If any element within x has no names (NULL), then the transposition is done based on positions. If all element within x have the same names, then the transposition is done based on those names.

Examples

# modeling example
iris_bySpecies <- split(x = iris, f = iris$"Species")
lmObj_bySpecies <- lapply(X = iris_bySpecies, FUN = function(dat) {
   lm(Sepal.Length ~ Petal.Width, data = dat)})
lmEl_bySpecies <- t_list(lmObj_bySpecies)
summary(lmObj_bySpecies); summary(lmEl_bySpecies)
summary.default(lmEl_bySpecies[[1]]); summary.default(lmEl_bySpecies[[2]])

# no names
lmObj_bySpecies2 <- unname(lapply(X = lmObj_bySpecies, FUN = unname))
lmEl_bySpecies2 <- t_list(lmObj_bySpecies2)
summary(lmObj_bySpecies2); summary(lmEl_bySpecies2)
summary.default(lmEl_bySpecies2[[1]]); summary.default(lmEl_bySpecies2[[2]])
all(unlist(Map(name = lmEl_bySpecies, nameless = lmEl_bySpecies2,
   f = function(name, nameless) all.equal(unname(name), nameless)))) # is everything
   # but the names the same?

# atomic vector example
x <- list("A" = c("a"=1,"b"=2,"c"=3),"B" = c("a"=1,"b"=2,"c"=3),
   "C" = c("a"=1,"b"=2,"c"=3))
t_list(x, rtn.atomic = TRUE)

# names in different positions
x <- list("A" = c("a"=1,"b"=2,"c"=3),"B" = c("b"=2,"a"=1,"c"=3),
   "C" = c("c"=3,"b"=2,"a"=1))
t_list(x, rtn.atomic = TRUE)

# no names
x <- list(c(1,2,3), c(1,2,3), c(1,2,3))
t_list(x, rtn.atomic = TRUE)

# lists with a single element
x <- list("A" = c("a"=1,"b"=2,"c"=3))
t_list(lmObj_bySpecies[1])